First of all there may be some truth in the whole monopoly thing but it's a slippery slope. What if I have developed a notepad application? Can I sue MS for bundling notepad? Or can I sue them for bundling Solitaire or Calculator? Although this would be terrible (presented with a ballot screen the first time you use anything) it can go deeper than that. Can Sun sue Microsoft because they bundle the .NET framework instead of the JVM?

Also I don't understand how Opera is going to gain marketshare this way (since they are the ones that pushing it). Let's say that an average user is presented with:

Internet explorer because it's what i use all the time
Firefox because I heard my nephew talk about it and he's really good with this stuff
Chrome because it says google
Safari because it says apple

So I don't see how Opera is going to benefit from a ballot screen. The browser that is going to benefit the most is chrome. Average people don't know the difference between a browser and a search engine, as demonstrated by a youtube video someone posted earlier (They shouldn't too. They just want their job done). So if they don't go with IE they are going to go with the second most familiar thing in that list.

PS: I am an Opera user since 9.2x and I consider it to be the best browser right now but I am really saddened by what they are doing